“If a man has sexual relations with his neighbor’s wife, then both the man and the woman are guilty of adultery. So both the man and the woman must be put to death!
God wants husbands and wives to become one body and one spirit. Why? So they would have holy children. So protect that spiritual unity. Don’t cheat on your wife. She has been your wife from the time you were young.
She might have sexual relations with another man and hide this from her husband. And there might not be anyone to tell him that she did this sin. Her husband might never know about the wrong thing she did. And the woman might not tell her husband about her sin.